The present invention relates to a semiconductor module, and more particularly to a semiconductor module in which semiconductor chips are mounted on a multi-layer wiring substrate.
Semiconductor modules of various structure in which semiconductor chips are mounted on a multi-layer wiring substrate have been developed. For instance, a multi-chip module having an improved thermal performance is described by Kohara et al. in a paper entitled "High-Thermal Conductive Module" in 35TH Electronic Components Conference, Proceedings 1985, pp 180-186.
In addition, a new packaging technology of LSI chip is described by Watari et al. in a paper entitled "Packaging Technology For The NEC SX Supercomputer" in the above-mentioned 35TH Electronic Components Conference, Proceedings 1985, pp 192-198.
Conventional semiconductor modules have adopted structure in which a face down semiconductor chip is fixed on a semiconductor substrate and then a cap is provided to cover the fixed semiconductor chip by adhering a die of the semiconductor chip to a surface of the cap opposite the substrate. When such a structure is employed, since the adhering or bonded portions cannot be visually confirmed or recognized, high precision technique is required for assembling work. In addition, since the number of individual bonded portions is also increased, the number of assembling steps is increased, resulting in lowered reliability of the module itself.